Various factors are involved in determining human skin color, and among them, factors, such as the activity of melanocytes, which make melanin pigments, the distribution of blood vessels, the thickness of the skin, and the presence or absence of pigments (e.g., carotenoid, bilirubin, etc.) in the human body, are of importance. The most important factor among them is black pigment melanin, which is produced by the action of various enzymes such as tyrosinase in human melanocytes. The formation of the melanin pigment is influenced by genetic factors, hormone secretion, physiological factors associated with stresses, and environmental factors such as UV light irradiation.
The melanin pigment, which is produced in melanin cells on the body skin, is a phenolic polymer having a complex of a black pigment and a protein. It blocks the sun's ultraviolet rays to protect the skin organs under the dermis and, at the same time, removes free radicals generated in skin tissues so as to protect proteins and genes in the skin. However, melanin, produced by internal or external stress stimuli in the skin, is a stable substance, which is not removed even when the stresses disappear, until it is discharged to the outside by skin keratinization. Thus, when melanin is produced in an unnecessarily large amount, hyperpigmentations, such as discoloration, freckles and spots, which are unfavorable in terms of beauty, will occur. As people who like outdoor activity have increased with an increase in leisure population, the need to prevent melanin pigmentation caused by UV light has increased. In order to satisfy this need, ascorbic acid, kojic acid, albutin, hydroquinone, glutathione, or derivatives thereof, or substances having tyrosinase inhibitory activity, have been used in cosmetics or medical drugs. However, the use thereof has been limited due to insufficient whitening effects and various problems, such as skin safety problems, and formulation and stability problems which occur when they are added to cosmetics.